Context

Forest loss and fragmentation are rapidly expanding across the tropics. Although forest loss is a major driver of the current biodiversity crisis, the effect of fragmentation remains debated, particularly for forest-specialist species.

Objectives

We evaluated the univariate and combined effect of forest loss (percent of forest cover) and fragmentation (forest patch density) on populations of a forest-specialist primate, the black-fronted titi monkey (Callicebus nigrifrons), in the landscapes from a transitional zone between Atlantic Forest and Cerrado biomes.

Methods

We surveyed titi monkey density in 14 landscapes. Using a multiscale and multimodel inference approach, we tested the relative effect of each landscape variable assessed at their respective scales of effect on titi monkey density.

Results

Titi monkey density ranged from 0 to 12 groups/km² and was best predicted by the combined effect of forest cover and patch density. Density increased in forest patches embedded in more deforested and fragmented landscapes. Interestingly, the effect of forest patch density was consistently positive along the entire evaluated forest cover gradient (9–42%).

Conclusions

Our findings support that fragmentation per se can have positive effects on biodiversity, in this case, by increasing the likelihood that more individuals can be ‘rescued’ from deforestation and crowded in the remaining forest patches. Although the long-term consequences of living crowded in forest patches are unknown, a conservative approach for preserving this (and potentially other) forest-specialist species could be to promote forest restoration projects focused on increasing the number and/or size of forest patches in the landscape (i.e., reverse fragmentation).

中文翻译：

---

森林丧失和破碎化可以促进森林专家灵长类动物的拥挤效应

语境

热带地区的森林消失和破碎化正在迅速扩大。尽管森林丧失是当前生物多样性危机的主要驱动因素，但碎片化的影响仍然存在争议，特别是对森林专业物种而言。

目标

我们评估了森林丧失（森林覆盖率百分比）和破碎化（森林斑块密度）对森林专家灵长类动物种群的单变量和综合影响，黑额猴 ( Callicebus nigrifrons )，在过渡区的景观中大西洋森林和塞拉多生物群系之间。

方法

我们调查了 14 个景观中的山雀密度。使用多尺度和多模型推理方法，我们测试了每个景观变量在它们各自的影响尺度上评估的对山雀密度的相对影响。

结果

Titi 猴密度范围从 0 到 12 组/km ²并且最好通过森林覆盖和斑块密度的综合影响进行预测。在森林砍伐和破碎化程度更高的景观中，森林斑块的密度增加。有趣的是，沿着整个评估的森林覆盖梯度（9-42%），森林斑块密度的影响始终是积极的。

结论

我们的研究结果支持碎片化本身可以对生物多样性产生积极影响，在这种情况下，通过增加更多个体从森林砍伐中“获救”并拥挤在剩余的森林斑块中的可能性。尽管在森林斑块中拥挤生活的长期后果尚不清楚，但保护这种（以及可能的其他）森林专业物种的保守方法可能是促进森林恢复项目，重点是增加森林斑块的数量和/或规模。景观（即反向碎片化）。